Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Title: Common esotropia and exotropias
Description: brief review of common esotropias and exotropias
Description: brief review of common esotropias and exotropias
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Common Esotropias and Exotropias
Presenter: Dr
...
Mutaz Gharaibeh
Basic Knowledge
•
The visual axis
Passes from the fovea, through
the nodal point of the eye, to
the point of fixation
...
•
Angle kappa is the angle,
Near reflex triad
•
Triad of:
1
...
Convergence
3
...
AC/A Ratio
•
Orthophoria
Perfect ocular alignment in the
absence
of any stimulus for fusion, very
uncommon
...
Exo- The eye is rotated so that
•
-phoria :
A latent deviation ( eg, esophoria, exophoria, right
hyperphoria) that is controlled by the fusional
mechanism so that the eyes remain aligned under
binocular conditions
...
Tropias can be constant or
intermittent
...
Acquired : A deviation with onset after 6
months of age
...
Monocular : Definite preference for fixation
with one eye
...
•
lncomitant (noncomitant)
The deviation varies in size in different positions of gaze or with
the eye used for fixation
...
•
•
Variable, transient, intermittent strabismus is
commonly observed in the first 2-4 months of life
...
Pseudostrabismus
Flat wide nasal
bridge
Light reflex
central
Evident
epicanthal folds
Light reflex
central
Esotropia
•
•
Esodeviations are the most common type of strabismus,
accounting for more than 50% of ocular deviations in the
pediatric population
Amblyopia develops in approximately 50% of children with
esotropia
...
Anisometropia and hyperopia
II
...
Prematurity, low birth weight,
IV
...
Chromosomal anomalies
VI
...
Family history of strabismus
...
•
Onset between 6 months and 7 years (average 2 – 3 years
...
•
Frequently associated with amblyopia
...
•
May follow trauma or ilness
Refractive Accommodative Esotropia
•
Esotropia that is restored to orthotropia at all fixation distances
and in all gaze positions by optical correction of the underlying
hypermetropic refractive error
...
00 &+7
...
§
Moderate degrees hypermetropia (3-5DS)
Fusional vergence not enough to overcome conv
...
§
High degree hypermetropia (>5DS)
patient remain straight or occasionally diverge
...
Correction of the full cycloplegic refraction
...
If binocular
fusion is maintained, the refractive correction can later be
decreased to 1
...
00 D less than the full cycloplegic
refraction
...
)
2
...
Parents must understand not only that full-time wear of the
glasses is important but also that the refractive correction
can only help control the strabismus, not cure it
...
Alignment within (8-10 PD) results in the
development of the Monofixation Syndrome
(peripheral fusion, central suppression)
...
1
...
2
...
4
...
In presence of amblyopia, surgery is performed on the
amblyopic eye
...
Non-Refractive accommodative esotropia
•
AC/A ratio is high
...
Convergence excess
...
Hypoaccommodative convergence excess
...
Normal near point of accommodation
Straight eyes with BSV for distance
Esotropia for near, usually with suppression
Straight eyes through bifocals
•
Hypoaccommodative convergence excess:
High AC/A ratio due to decreased accommodation
Remote near point of accommodation
...
Esotropia for near, usually with suppression
...
00 D)
...
The process of reducing the
bifocal power in 0
...
00 D steps can be started at
about age 7 or 8 and should be completed by age 10-12
years
...
Contraindication is amblyopia and not complete
elimination of ET in near
...
Management
Surgery:
Medial rectus muscle recessions with or without
posterior fixation or pulley fixation
...
Therefore, if the esotropia with glasses
increases, the cycloplegic refraction should be
repeated and the full correction prescribed
...
•
Onset usually before age 5 years
...
Deviation usually noted first for distance vision
Exposure to bright light often causes a
reflex closure of 1 eye
...
Untreated intermittent exotropia may
progress toward constant exotropia
Progression of Exotropia
•
Phoria Tropia
•
Distance deviation Near deviation
•
Progression more rapid under age 6, but
progression in adulthood common
also(may present with diplopia)
Duane’s Classification
1
...
3
...
Simulated (Pseudodivergence excess) exotropia is the most common form of intermittent
exotropia
...
00 D lenses at near
...
It is present
when the distance deviation is greater than the near deviation, and the deviation does not
equalize after monocular occlusion or with +3
...
Basic exotropia is present when the exodeviation is approximately the same at distance and near
fixation
Convergence weakness exotropia is present when the exodeviation is greater at near than at
distance
(Difference of at least 15 PD)
•
•
•
Good control: Exotropia manifests only after cover testing,
and the patient resumes fusion rapidly without blinking or
refixating
...
Poor control: Exotropia manifests spontaneously and may
remain manifest for an extended time
...
Correction of refractive errors :
Significant myopic, astigmatic, and hyperopic refractive errors
(>+4
...
50 D hyperopic anisometropia)
...
00-4
...
•
Occlusion therapy :
Patching of patients with amblyopia may improve
control of exotropic deviations
...
•
•
Prisms for Exotropia
Base In Prisms useful in
–
–
•
Small angle exotropia
For reading with convergence insufficiency
Base out Prisms:
–
Temporary treatment of esotropia after exotropia surgery
Surgery
•
1
...
Progression toward constant exotropia
Simulated: symmetric recession of both LR muscles is the
most common surgical procedure
...
Title: Common esotropia and exotropias
Description: brief review of common esotropias and exotropias
Description: brief review of common esotropias and exotropias